Apparatus for processing ore



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Filed April 13, 19s? APPARATUS FOR PROCESSING 01m 2 Sheets-Sheet 1 INVENTOR CARL L. JOHNSON ATTORNEY May 12, 1970 f i c. L- JOHNSON 3,511,445v

APPARATUS FOR PROCESSING ORE Filed April 15, 1967 2 Sheets-Sheet- 2 minim...

INVENTOR CARL L. JOHNSON BY /",lv -=1""' 5 M.

ATTORNEY United States Patent US. Cl. 241-452 7 Claims ABSTRACT OF THE DISCLOSURE Mineral values are separated from low-grade ore first by passing the ore through convergent banks of rollers where, as opposed to crushing the ore, it is broken down to its basic particle size. Separation of the mineral values is carried out in a scrubber or separator wherein the particles are scrubbed, abraded and broken apart by impact in a succession of rotary stages in which the particles are caused to undergo a constant change in direction at a relatively high speed whereby the oxides are scrubbed from the external surfaces of the particles as the particles are rubbed against one another and against the blades under a combined centrifugal and centripetal action. The

mineral values are then separated from the gangue and classified according to size.

This invention relates to a novel and improved apparatus for processing ore; and more particularly relates to an improved method and apparatus which will achieve high percentage recovery of mineral values from lowgrade ore at a relatively low cost.

The present invention has particular utility in efficiently obtaining mineral values from low-grade ore, such as for example, the recovery of copper oxide coatings from barren rock or uranium oxide coatings on particles or grains of sand. Generally the oxides are cemented or attached to the gangue to form solid rock masses, and very often the cementitious material between the gangue and the oxide coatings also contains valuable and desirable mineral oxides. In order to successfully remove the mineral values from the low-grade ore at a relatively low cost, it has been found that this can be most efficiently and feasibly accomplished by breaking the rock masses down to a basic particle size and in such a way as to avoid crushing of the ore to a size smaller than its basic particle size. Thereafter the mineral oxide values may be most efficiently removed through a combined scrubbing, abrading and impact operation. The particles of or usually have a slight moisture content and because of the relatively small size of the ore particles the presence of moisture tends to reduce the speed at which the ore may be moved to separate mineral values. This is satisfactorily overcome in the present invention by partially drying the material during scrubbing operations.

Some apparatuses for separating mineral values from the host rock have employed water and liquid chemicals. This has sometimes resulted in contaminating and diluting the mineral values to such an extent that it is not economically feasible to separate the values from lowgrade ore. Additionally, these apparatuses have required a source of water. The present invention utilizes an apparatus in which there is no requirement for water or liquid chemicals so that the apparatus may readily operate in areas having a low-grade ore deposit and in which there is no source of available water in the quantity required by prior methods.

Once the mineral values are separated from the gangue or host rock it is further desirable to provide an efiicient means of classification and removal of the mineral values according to size as a part of a continuous process. in which the mineral values can be removed and collected by size for immediate shipment.

It is therefore an object of the present invention to pro- "ice vide a novel and improved apparatus for economically removing mineral values from low-grade ore.

It is another object of the present invention to provide an apparatus for separating mineral values from lowgrade ore in which the ore can be broken down into basic particle size and the mineral values separated from the ore with partial drying of the ore particles during the separation process.

It is a further object of the present invention to provide for a compact, portable apparatus for reducing ore particles to a predetermined size in accordance with the type of ore, the ore district and the natural particle size of the ore; further wherein the mineral values may be more efficiently separated in a combined scrubbing, abrading and impact operation for subsequent removal and accurate classification of the mineral values.

In accordance with the present invention, low-grade ore is broken down to particle size through a convergent roller path. From the roller stage, the ore particles are delivered through a separator where in each of a succession of stages the particles are first thrown outwardly by centrifugal :force to impinge against the wall of the separator housing and then are returned inwardly by centripetal blades for the purpose of directing the particles inwardly for advancement to the next stage. The combined centrifugal and centripetal action imparted to the particles cooperate in further breaking the materials down to basic particle size and, most importantly, scrubbing the mineral oxide values from the external surfaces as the particles are rubbed and abraded against one another and thrown by impact against the blades and against the wall of the housing. Moreover the particles are partially dried in advancing through the separator housing for increased ease of movement and scrubbing between the particles in the efiicient removal of the mineral oxide values. Thereafter the mineral oxide values and host rock are advanced through a classifier and air movement, the mineral values can be separately removed and classified according to size in a unique, highly simplified manner. In the apparatus, the scrubber stage includes rotating elements disposed within the housing and vertically spaced from one another to define a series of stages in which the ore particles are first directed outwardly between circumferentially spaced radial blade elements for impingement against the wall of the housing and thereafter are returned inwardly by arcuate blade elements to the center of the housing for advancement to the next stage. The stages are most desirably divided into separate chambers and each chamber having means to permit limited communication between the chambers whereby the ore particles may advance along a controlled path of travel between each stage. The last stage includes means at the bottom of the housing to define an exhaust for removal of the gangue and separated mineral values to the classifier stage.

The above and other objects, advantages and features of the present invention will become more readily understood and appreciated from a consideration of the following detailed description of a preferred form of apparatus of the present invention when taken together with the accompanying drawings, in which:

FIG. 1 is a schematic view of the apparatus of the present invention for separating mineral values from lowgrade ore.

FIG. 2 is a vertical sectional view, partially in elevation, of the scrubber or separator housing of the apparatus of FIG. 1.

FIG. 3 is a top plan view of one of the rotating structures within the separator or scrubber housing of FIG. 2.

FIG. 4 is a bottom plan view of one of the rotating structures within the separator or scrubber housing other than the bottom rotating structure; and

FIG. is a bottom plan view of the bottom rotating structure within the separator or scrubber housing of FIG. 2.

Referring to the drawings and particularly FIG. 1, there is shown in combination an ore reducer 10, a separator or scrubber 11, and a classifier 12. The low-grade ore is initially directed through the reducer in which the size of the particles of the ore is reduced by breaking down to a maximum predetermined size. The ore particles are then transported by directing or conveying means 14 to the scrubber or separator 11. After the mineral values are separated from the host rock or from the grains or particles of sand, the separated mineral values and the gangue are transported through a duct 15 to the classifier 12. The duct 15 has air moving means 16, such as, a fan disposed therein to advance the mineral values and the gangue therethrough.

The reducer 10 includes a frame 17 which has a first pair of inclined support members represented at 18. A lower bank or rollers 19 extends between the horizontally spaced support members 18 and each is supported at opposite ends by means of suitable bearings 18 above the support members 18.

The frame 17 has a second pair of inclined support members which are disposed above the first pair of inclined support members 18 and at an angle to the support members 18. An upper bank of rollers 21 extends between the horizontally spaced support members 20 and each is supported at opposite ends by bearings 21' depending downwardly and inwardly from the support members 20 toward the first bank of rollers. The rollers 21 are disposed in offset relation to the lower bank of rollers 19 and because of the convergent relation of the support members 18 to the support members 20, a convergent path exists between the rollers 21 and the rollers 19 so that the spacing between banks of rollers is progressively reduced in a downward direction toward the lower, outlet end. The distance between the two banks of rollers is variable, and which distance may be determined and controlled by adjustably mounting the rollers 21 with respect to the support members 20 through the respective bearings 18' and 21.

Screens 23 are mounted in spaced relation above the support members 18 whereby to traverse the width of the rollers and to extend between each adjacent pair of the rollers 19. The mesh of the screens 23 is such that only particles within a predetermined size will pass therethrough, and the remaining particles will continue to move downwardly along the convergent path toward the lower end. The ore particles passing through the screens 23 are collected by the conveyor means 14, the latter being preferably defined by a conventional conveyor belt 24 supported by rollers 25 and 26 and including suitable drive means, not shown.

The remaining ore particles which do not drop through one of the screens 23 eventually pass between the lowermost of the rollers 19 and 21, which are disposed in adjacent, offset relation to one another and closest to the conveyor belt 24. The spacing of these two lowermost rollers is such that all remaining particles of the lowgrade ore will be no greater than the maximum predetermined size of the particles allowed to pass through the screens 23, and at the end of the roller stage the remaining particles also fall onto the conveyor belt 24.

The scrubber or separator 11 generally includes a support stand 27 for a cylindrical housing 28. A drive shaft 29 extends through the housing 28 at the longitudinal axis thereof and is supported by an upper bearing 30 and a lower bearing 31 on the support stand 27. The shaft 29 is driven by a suitable prime mover, such as, the motor 32 which is supported on the support stand 27 and drives the shaft 29 through pulleys 33 and 34 and connecting belts 35. The speed of the motor 32 may be varied to rotate the shaft 29 at different speeds in accordance with the type of ore and the type of mineral values coated or deposited on the barren rock or sand of the ore.

As shown in FIG. 2, the scrubber housing 28 has its top 36 closed except for an opening through which an ore chute or hopper 37 extends. Similarly, the housing 28 has its bottom 38 closed except for an exit opening 39 therein to permit communication from the interior of the housing 28 to a duct 40 communicating with the duct 15. Rotary members 41, 42, 43 and 44 are fixed for rotation about the axis of the shaft 29, each having a hub 45 secured to the shaft 29 and an annular plate 46 extending from the lower portion of the hub 45 and fixedly connected thereto. Each of the members 41, 42 and 43 includes equally spaced, upstanding radial blades 47 extending outwardly from the center of the rotatable member 47 and terminating adjacent to but short of the periphery of the annular plate 46 as shown in FIG. 3.

If desired, an annular cover plate 48 may be attached to the upper surface of each of the blades 47, and the plate 48 has a sufiiciently large opening 49 at its center to permit the passage of material therethrough onto the space formed between the plates 46 and 48. In turn, each of the members 41, 42 and 43 has a plurality of centripetal blades 50 depending downwardly from the lower surface of the annular plate 46 at equally spaced intervals and fixedly secured to the plate 46. As shown in FIG. 4, the centripetal blades 50 are of arcuate or generally semi-circular configuration and extend from a point near the center and terminate outwardly of and beyond the outer periphery of the plate 46.

The outer rotary member 44 has the same construction as the members 41, 42 and 43 insofar as the hub 45, the annular plate 46, the blades 47 and the annular plate 48 are concerned. However, in place of the centripetal blades 50 along the lower surface of the plate 46, a plurality of equally spaced, radial bafiles 51 extend downwardly from the lower surface of and along the outer peripheral edge of the plate 46, as best seen from FIG. 5. Here the bafi'les are aligned for movement through a channel 52 between the wall of the housing and an upstanding, annular portion 52' of the bottom 38 of the scrubber or separator housing 28.

Annular plate members 53, 54 and 55 are supported at vertically spaced intervals to divide the housing 28 into a plurality of chambers 56, 57, 58 and 59 between each of the respective rotary members 41 and 44. Each of the annular plates 53, 54 and 55 has a central downwardly tapered passage 60 to permit communication between each successive stage. The passage 60 tapers so that it is smaller in diameter than that of the aligned adjacent opening 49 in the plate 48 above which it is disposed, as shown in FIGURE 2, thereby to insure that the material flowing therethrough is confined for movement onto the plate 46 of each next rotary member in succession.

When the ore particles flow into the housing 28 through the ore chute 37 from the conveyor belt 24, they are directed through the central opening 49 in the annular plate 48 of the rotatable member 41 onto the upper surface of the plate 46 of the member 41. Rotation of the member 41 causes the particles to be thrown outwardly from the center and make contact with the rotating blades 47 and be scrubbed and tumbled while being continuously advanced outwardly for impingement against the inner wall of the housing 28. As the ore particles are forced outwardly, they are partially dried to reduce their slight moisture content for greater acceleration of the particles prior to striking the inner wall of the housing 28, and will tend to collect along the blades and follow the rotational movement of the blades in being advanced outwardly so as to result in constant scrubbing and abrasion between the particles. The particles are further reduced in size and separated upon striking the inner wall and will advance downwardly further along the inner housing wall and be picked up by the centripetal blades 50 which will reverse the direction of movement of the ore particles and the separated mineral values toward the center. As the particles are moved inwardly by the centripetal blades 50, they will continue to engage and impinge against one another and against the centripetal blades whereby additional separation of the mineral valu s from the ore particles may occur.

When the ore particles and the mineral values are returned to the center they are free to pass through the tapered passage 60 into the next chamber 57, and specifically all of the separated fines of the mineral values and the ore particles will flow through the opening 49 onto the annular plate 46. The process in the first chamber 56 is repeated in each next chamber or stage in succession, it being understood that a sufficient number ofstages or chambers are utilized to assure complete separation of the mineral values, depending upon the characteristics of the material. In the outlet stage, i.e., the lowest chamber 59, the ore particles and the mineral values are directed by the guide members or bafiies 51 through the exit or outlet o ening 39 in the bottom 38 of the housing 28. The mner wall of the housing 28 has inclined ribs 61 as shown in FIG. 3 which cooperate with the baflles 51 to aid in directing the mineral values and the gangue, that is, the ore particles from which the mineral values have been removed, into the duct 40 through the outlet or exit opening 39.

The duct 40 communicates with the duct leading into the classifier 12; and the air moving means 16 induc s a negative pressure within the scrubber or separator housing 28 to draw the ore particles and mineral values 0 through the housing 28 and through the exit opening 39 into the duct 40. As shown in FIG. 1, the interior of the housing of the classifier 12 has an arcuate bafile 62 cooperating with the inner wall of the housing of the classifier 12 to define an upwardly convergent peripheral path for upward flow of the mineral values from the inlet of the classifier 12. A vertical duct 64 extends upwardly from the top of the classifier 12 and communicates with the upper exit end of the convergent path. The duct 64 has a series of stacks 65 disposed in vertically spaced relation to one another. According to the vertical distance or spacing of the stacks above the classifier housing each will conduct fines of a different size range away from the housing for collection in product bins or for loading according to size. For example the lower stack may serve to collect fines in the range of 90 to 110 mesh, the next stack in the range of 100 to 130 mesh, the next stack in the range of 125 to 170 mesh and the uppermost stack in the range of 160 and above. For example in collecting uranium oxide the highest values generally would be in the mesh sizes greater than 160.

The weight of the heavier gangue particles, being greater than the weight of the fines or mineral values, will not rise through the convergent path but will settle at the bottom of the housing of the classifier 12 and drop through a discharge gate 63. Similarly the gangue which is transported to the upper end of the path will not be sufficiently light in weight to be carried into the outlet duct 64; instead it will return through the open area of the classifier, in the direction of the arrows, for collection in the discharge gate 63. In this connection the discharge gate 63 is located in the path of air flow through the duct 40 so that any lighter weight particles entrained in the gangue maybe recirculated.

Considering the operation of the present invention, the low-grade ore is deposited within the reducer 10 and advanced downwardly between the banks of rollers 19 and 21. Some of the ore particles are reduced sufficiently in size to pass through the screens 23 while the remainder of the ore particles are reduced to a maximum predetermined size before leaving the path of the rollers 19 and 21. Thus, all of the ore particles directed onto the conveyor belt 24 have a predetermined maximum size depending on the mesh of the screens 23 and the relative distance between the lowermost of the rollers 19 and 21. It should be understood that the rollers 19 and 21 are positioned so that there will be no crushing of the particles beyond a minimum size.

The conveyor belt 24 directs the ore particles into the ore chute 37 from which the ore particles flow into the housing 28 of the scrubber or separator 11. The air moving means 16 insures that the ore particles and the sep arated mineral values flow through the housing 28. The rotary members 41, 42, 43 and 44 serve both to partially dry the ore particles during each stage as well as to separate some of the mineral values from the ore particles.

The separated mineral values and the gangue fiow from the housing 28 of the separator or scrubber 11 into th housing of the classifier 12. The heavier gangue is collected and escapes through the gate 63 as described. The mineral values flow through the restricted convergent path in the housing of the classifier 12 into the vertical duct 64 and are exhausted through one of the vertically spaced stacks 65 depending on their size and weight.

While three of the rotatable members 41, 42 and 43 are shown disposed above the rotatable member 44, it will be understood that the speed of the rotation of the shaft 29 may be varied and is largely determined by the type of ore and the particle size of the rock or sand forming the ore. While the directing or conveying means 14 has been shown as a flat conveyor belt 24, it will be apparent that other suitable types of transporting means could be employed; for example, a series of bucket conveyors may be utilized. It will be further evident that the rollers 19 and 21 are driven in a direction to move the particles from the top of the frame 17 to the bottom of the frame 17; thus, the rollers 21 rotate clockwise and the rollers 19 counterclockwise.

An important feature of this invention resides in the high percentage recovery of mineral values from lowgrade ores at a relatively low cost. Another advantage of this invention is that it eliminates the need for water in a mineral recovery process, and the recovery process can be carried out with a compact, portable apparatus.

While the preferred form of apparatus for processing ore of the present invention has unique application as described, it is nevertheless to be understood that various modifications and changes may be made in the detailed construction and arrangement of elements comprising the preferred form of invention as well as its intended use Without departing from the spirit and scope of the present invention as defined by the appended claims and reasonable equivalents thereof.

What is claimed is:

1. An apparatus for separating mineral values from ore, said apparatus comprising a scrubber having a housing, a plurality of separating chambers disposed in vertically spaced relation to one another within said housing with adjacent chambers being in limited communication with one another at their centers, means to introduce ore particles into the uppermost of said chambers, each of said chambers being divided to provide upper rotatable means to direct ore particles outwardly from the center for impingement against said housing and lower rotatable means having means to return the ore particles toward the center for advancement to each next chamber in succession, each of said chambers having means to permit communication between said chambers whereby the ore particles and any separated mineral values may pass from each of said chambers to the next chamber in succession, means positioned beneath the lowermost chamber to close the bottom of said housing, said closing means having an exit opening therein, and the lower rotatable means in the lowermost chamber having means disposed beneath said upper rotatable means to direct the ore particles and the separated mineral values through said exit opening.

2. The apparatus according to claim 1 in which said rotatable means includes a shaft and means to rotate said shaft, said upper and lower rotatable means in each chamber including an annular plate therebetween being rotatable with said shaft and supported there-by, each of said upper rotatable means having blade members extending radially outwardly from adjacent the center of each of said upper rotatable means along the upper surface of said plate to cooperate with said plate to form said centrifugal directing means, said lower rotatable means having centripetal blades attached to the lower surface of said plate to form said return means.

3. The apparatus according to claim 2, said lower rotatable means in the lowermost chamber having radial guide members attached to the lower surface of said plate, said guide members extending beyond the periphery of said plate to define said exit directing means.

4. The apparatus according to claim 3 including inclined ribs disposed on said housing in spaced relation to each other to cooperate with said radial guide members in directing the gangue and the separated mineral values through said exit opening.

5. Apparatus for separating mineral values from ore, said apparatus comprising a housing, means to introduce ore into the upper portion of said housing, at least one separating chamber disposed for rotation within said housing including a central shaft and means to rotate said shaft, said chamber including an annular plate supported for rotation on said shaft, upper rotatable means on said plate to receive ore introduced into said housing and to direct the ore outwardly in a radial direction for impingement against said housing and lower rotatable means defined by circumferentially spaced, centripetal blades attached to the lower surface of said annular plate to return the ore impinged against the housing toward the center of said housing.

6. Apparatus according to claim 5 in which said upper rotatable means is defined =by circumferentially spaced blade members extending radially outwardly along the upper surface of said annular plate whereby to cooperate with said annular plate in forming centrifugal directing means for the ore.

7. Apparatus according to claim 5, said lower rotatable means having radial guide members attached to the lower surface of said annular plate, said guide members extending beyond the periphery of said plate.

References Cited UNITED STATES PATENTS 812,122 2/1906 Fassett 241-154 1,483,241 2/ 1924 Opderbeck. 2,573,129 10/1951 Dulait 24l275 X 2,591,141 4/1952 Dulait 241-275 X 2,943,801 7/1960 McIlvaine 241124 3,044,720 7/ 1962 Bridgewater 241275 3,065,919 11/1962 Burkett 241275 X 3,160,354 12/ 1964 Burkett 241-275 3,180,582 4/1965 Daryluke 241275 ROBERT C. KELLY, Primary Examiner D. G. KELLY, Assistant Examiner U.S. Cl. X.R. 241-275 

